I. Technical Field
The present invention relates generally to a pressure relief valve, and more particularly, to a pressure relief valve which reduces the build-up of debris therein.
II. Discussion
Lubrication systems play a critical role in the operation of many different types of machinery. For instance, lubrication systems play a critical role in internal combustion engine performance and operation. Typical internal combustion engines have a number of components which move and wear against one another causing frictional wear. This wear, over a period of time, compromises the performance and durability of the engine as a whole. To combat this wear, internal combustion engines are fitted with a lubrication system which provides oil to these components, thereby reducing frictional wear and increasing the life of the engine. Without this lubrication system, the engine would most certainly self-destruct within a short period of time.
Full pressure lubrication systems for internal combustion engines use an oil pump to circulate oil to the necessary components. This pump, itself, is driven by the internal combustion engine. Typically, this pump has a greater capacity than the engine requires for sufficient circulation of oil. This ensures that all the critical components within the engine are lubricated, irrespective of the speed at which the internal combustion engine is operating. However, similar to deprivation of oil, excessive pressurization of oil can result in the destruction of critical components within the engine. Specifically, over pressurization may result in the destruction of the oil filter or other components of the engine lubrication system. To combat this problem, oil pumps are fitted with pressure relief valves. These valves vent oil back to the engine lubrication system's sump when the oil pressure becomes too high, thus maintaining a constant oil pressure.
Usually, these valves have a piston positioned within a cylindrical bore which is biased in one direction by a spring. Pressurized oil from the oil pump applies a force on the piston which is opposite to the spring. As the oil pressure increases, the spring is compressed, causing movement of the piston which exposes oil vents or the edge of the piston. These vents allow oil to pass back to the sump or pump. However, this system has some drawbacks.
Debris tends to collect in certain areas within the vents, causing the piston to stick in one position or another. If the piston is stuck closed, not allowing oil to vent back to the sump or pump, then the lubrication has no way to vent high pressure resulting in the damage as discussed above. If the valve is stuck open, then oil vents backs to the sump or pump irrespective of the oil pressure, thereby starving the internal combustion engine components of oil. As discussed previously, this results in self-destruction of the engine. The present invention was developed in light of these drawbacks.